FL: Black Vultures chow down
on city hall's roof ... also
munch on pipe insulation and
window caulking ...
(Daytona Beach News-Journal)
Vultures are in for a shock at DeLand City Hall.
After pecking at the $150,000 roof for a couple of months, the roughly 60 black vultures that lounged there daily are going to experience an electric jolt if they land on the recently installed "bird shock flex-track system."
It's not lethal, but just enough to condition them from coming back to the building that sustained $1,000 in damage. The system cost the city about $11,000, city officials say, and DeLand isn't alone in its battle against voracious vultures with a penchant for ripping apart rubber.
Black and turkey vultures are federally protected migratory species, so options for managing the birds depend on site conditions. Federal permits also are required to kill or relocate the animals. While the scavengers play an important role in the ecosystem by feeding mostly on dead animals, conflicts with people and buildings are a costly nuisance that goes beyond bird droppings on a window.
Over the years, the birds have chewed up cable insulation on communication towers and have been known to damage cars at a medical center in Port Orange, officials say. People use everything from pyrotechnics to balloons to get them to move on.
If you're noticing more of nature's cleanup crew these days, that's because the turkey vulture -- some of which are here year round -- migrated for the winter.
This fall, DeLand city employees found themselves in "uncharted territory" when black vultures --year-round residents -- landed on the 13,000-square-foot City Hall roof. They chewed on the 3-year-old roof's rubber membrane and adhesives, insultation around the air-conditioner piping and caulking around the building's windows.
It could have led to leaks, City Manager Michael Pleus said.
"Nobody knew how to handle this -- not even our animal control guys," he said.
The city "landed" on the shock system after hearing about its effectiveness at other buildings in Central Florida, Pleus said.
Before installing the system, a city crew pressure-cleaned the vulture droppings from the roof. The urine is known to be highly acidic and corrosive, and it proved to be such a filthy task, the city's crew members had to trash their clothes.
The system will probably be activated today, though the birds haven't been seen since Massey Services began installing the shocking strips about two weeks ago.
Halifax Health-Medical Center of Port Orange has been dealing with flocks of turkey vultures intermittently since 1999. There aren't any currently, said spokeswoman Salina Wang, but in the past they have damaged the rubber around car windshields, windows and wiper blades, in addition to scratching paint jobs.
Halifax has used lots of tactics to keep the birds away, including installing spikes around the building perimeter, large balloons called "terror eyes" and a "squawk box" that makes periodic squawk sounds.
Wildlife researchers aren't sure why vultures have a taste for rubber.
It may have something to do with the gaseous odor the materials emit, said Michael Avery, a wildlife research biologist with the U.S. Department of Agriculture.
"That was one of the things we were investigating a few years ago," Avery said. "We had some birds in here and did some trials."
Researchers extracted some of the volatile chemicals from the materials and tried to conduct choice tests with the vultures to see if there was an attraction. The theory hasn't been disproven, but more work needs to be done.
Their attraction to roofs, though, can be attributed to the sun.
"A lot of buildings and a lot of houses experience problems because the birds leave their roost in the morning and they like to loaf around and get a good place where the sun hits," Avery said. "They can warm up before they take off searching for food or they may stay there all day. They don't have to eat every day."
Being up high also helps them find pockets of warm air, or thermals, that can carry them upward.
Over the years, vultures have found perching places at Volusia County's communication towers and the Emergency Operations Center roof, which had to be replaced because of leaks caused by the birds.
"The vultures tend to like the heat of the communication tower," county spokesman Dave Byron said. They also have a taste for cable insulation.
The birds caused more than $50,000 in damage, he said.
To deal with the invasion, the county got a federal permit to shoot a maximum of 20 vultures per year.
About five vultures have been shot since 1996, Byron said. County staff also uses a noisemaker, similar to a firecracker, to scare them off.
Workers at Daytona Beach International Airport regularly fend off birds of all species to prevent accidents with planes. During this time of year, sea gulls are more common, spokesman Steve Cooke said.
The airport also has a permit to kill birds, though none has been harmed. Instead, workers use propane cannons that sound similar to fireworks and handheld noisemakers to chase them off the runway.
Florida has two kinds of vultures, turkey and black vultures, which have bald heads so bits of dead meat don't stick to feathers
